Placental cis-eQTL study identifies preeclampsia-dependent genetic regulation at gene promoters

Researchers working with data from the FINNPEC cohort have posted a bioRxiv preprint reporting cis-expression quantitative trait locus (cis-eQTL) analyses of placental tissue from 59 pregnancies. The study uses 5′-end RNA sequencing to capture both gene-level and promoter-level expression — the latter defined as Transcript Far 5′ Ends — and performs separate analyses for maternal and fetal genotypes.

A key analytical feature is a genotype-by-preeclampsia interaction model, designed to detect genetic effects on placental transcription that are present or enhanced specifically when preeclampsia (PE) is present. The authors report that no gene-level eQTLs reached significance in interaction models, but promoter-level analyses identified candidate regulatory variants whose effects differed according to PE status. This suggests that some genetic influences on placental gene regulation may be context-dependent in ways that bulk gene-level measurements obscure.

Preeclampsia is a hypertensive disorder of pregnancy with contributions from both maternal and fetal genomes; how those genomes jointly regulate placental transcription has been incompletely characterised. The findings from this study may inform future functional work on candidate regulatory variants, though the sample size of 59 pregnancies limits statistical power and the preprint has not yet undergone peer review.

This is a preprint. Results and interpretations are preliminary and subject to change.